docs: Update README with latest applications list [skip ci]

Author: github-actions[bot]

README.md

@@ -22,6 +22,7 @@ A curated collection of Docker run commands that can be easily deployed via [Dep
   - [eBook](#ebook)
   - [File Sharing](#file-sharing)
   - [Finance](#finance)
+  - [Forum](#forum)
   - [Monitoring](#monitoring)
   - [Notifications](#notifications)
   - [RSS](#rss)
@@ -111,6 +112,10 @@ See [CONTRIBUTING.md](CONTRIBUTING.md) for detailed instructions.
 
 - [actual](commands/actualbudget/) - A local-first personal finance app
 
+### Forum
+
+- [Artalk](commands/artalk/) - 🌌  Your Self-hosted Comment System. | 自托管评论系统
+
 ### Monitoring
 
 - [changedetection.io](commands/changedetection/) - The best and simplest free open source web page change detection, website watcher,  restock monitor and notification service. Restock Monitor, change detection. Designed for simplicity - Simply monitor which websites had a text change for free. Free Open source web page change detection, Website defacement monitoring, Price change notification